Portable grinding machine



Jan. 4, 1955 c. E. MARSH PORTABLE GRINDING MACHINE 5 Shee'ts-Sheet 1Filed July 12, 1951 INVENTOR. CLAUDE E. MARSH BY ATTORNEY Jan. 4, 1955c. E. MARSH PORTABLE GRINDING MACHINE 5 Sheets-Sheet 2 Filed July 12,1951 IN VEN TOR. CLAUDE EMARSH FIG. IO

FIG. II

ATTORNEY Jan. 4, 1955 c E. MARSH PORTABLE GRINDING MACHINE 5Sheets-Sheet 3 Filed July 12, 1951 FIG. |2

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PORTABLE GRINDING MACHINE Filed July 12, 1951 5 Sheets-Sheet 4 4 U1 4 Ql 4| p 1 0 H6 144 :H TFH45 T 1 5 lJ I I C: 2

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. INVENTOR. CLAU DE E. MARSH BY a) ATTORNEY Jan. 4, 1955 c. E. MARSHPORTABLE GRINDING MACHINE 5 Sheets-Sheet 5 Filed July 12, 1951 H 3 MR.\.A M M. E E D U A. L C

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ATTORNEY United States Patent PORTABLE GRINDING MACHINE Claude E. Marsh,Atlanta, Ga., assignor to Herman F. Anderson, Kalamazoo, Mich.

Application July 12, 1951, Serial No. 236,289 8 Claims. (Cl. 51-241) Myinvention pertains to portable grinding machines in general, but more inparticular to a portable grinding machine for the crank pin journals oflocomotives or other large engine crankshafts.

In the repair and maintenance of locomotives and other large engines,particularly with reference to the grinding of crankshafts therefor, itis well known that such a repair job is both tedious and expensive. Thepiston and rod assemblies must be removed, the main bearingsdisassembled, and the complete crankshaft taken from the engine and setup in an expensive turning lathe where the grinding takes place. Sogreat is the cost of such an operation that often a single scored orbadly worn pin found by an inspection crew is left in operation untilits condition approaches the point of danger to the actual performanceof the engine. It is apparent that the same procedure must be followedfor the repair irrespective of whether a single pin or all of them arein need of grinding.

It is an object of my invention to provide a portable machine forgrinding the journals of an engine crankshaft without the necessity ofremoving the crankshaft from the engine.

It is another object of the invention to provide a centering device bywhich the machine is mounted on the crankshaft to automatically providethe proper eccentricity between the main bearing pin and the rod pin.

Another object of the invention is to provide such a machine which ismade in two semi-circular sections; each section including relatedcomponents operable for grinding upon being joined around the pin of thecrankshaft.

A further object of the invention is the provision of a novel grindingwheel assembly which is made not only to revolve slowly around the pinwhen grinding, but which is also made to move backwardly and forwardlyalong the longitudinal axis of the shaft. The assembly further includesprovision for dressing the grinding wheels and also supplying the powerfor reciprocating them across the pin journal.

Another object of the invention is the provision of a combination Vpulley and internal spur gear which is made to revolve in one directionwhile turning the joined sections of the grinding assembly in theopposite direction, thus putting the higher speeds on the internalgrinding parts while permitting the heavy outer assembly to turn at arelatively low speed.

Other objects of the invention are: the provision for ti htening orloosening the belts which rotate the grinding wheels, control of thedepth of the grinding wheels and means for checking the depth ofgrinding in thousandths of an inch from any starting position.

With these and other obiects in view, the invention consists of anarrangement of arts according to the accomnanying drawin wherein likecharacters of reference desi nate corresponding parts throughout thedrawing and wherein:

Fig. l is an elevational view of an embodiment of my invention in aportable crankshaft grinder, the same being shown assembled upon aportion of a crankshaft to be gr und and arranged for use with anelectric motor.

Fig. 2 is an end view of the assembly shown in Fig. 1.

Fig. 3 is a side view of what may be called a right-hand adapter. thetwo halves thereof being shown together as if encircling a portion of acrankshaft.

Fig. 4 is an exploded view illustrating the manner of assembly of thetwo-section device around a crankshaft.

Fig. 5 is a broken, cross-sectional view illustrating the mode ofassembling a gear train in a general housing member.

Fig. 6 is a detail view taken substantially along the line 66 of Fig. 5.

Fig. 7 is a broken view of one of the two main sectional members showingthe internally positioned gear train more in detail.

Fig. 8 is an enlarged detail view illustrating the manner of mountingthe externally driven V belt.

Fig. 9 is a detailed view of the main drive gear and pulley.

Fig. 10 is a detail view illustrating the manner of joining the twosemi-circular portions of the main drive gear.

Fig. 11 is another broken view illustrating the manner of locking thetwo semi-circular gear portions so as to form a true circular gear.

Fig. 12 is a broken view of the other of the two main sections of thegeneral machine illustrated in Fig. 1, this view illustrating themechanisms used in connection with the actual grinding.

Fig. 13 is a detail view of the combined pulley and belt arrangementused to rotate the grinding Wheels.

Fig. 14 is a top view of the reciprocating grinding wheel bracket.

Fig. 15 is a detail view showing the rear side of the grinding wheelbracket.

Fig. 16 is an enlarged view illustrating the manner of setting thegrinding wheels to a desired depth.

Fig. 17 is another detail view illustrating a portion of the reversemechanism actuating the traverse of the grinding wheels across the pinjournal.

Fig. 18 is a cross-sectional view illustrating the manner of sliding themain driving pinion of the grinding assembly into and out of a side wallof the housing proper in order to be entrained with the main drive gearpositioned in one of the outer positioning adapters.

Fig. 19 is a front view of a reversing assembly which actuates thetraverse of the grinding wheels across the pin journal.

Fig. 20 is a side view of the illustration shown in Fig. 19.

Fig. 21 is a side view of a centering device used in connection wi h thepresent invention to provide a concentric, radial osition of the twoprimary adapters with respect to the offsets on the crankshafts to beground.

Fig. 22 is a front view of the device illustrated in Fig. 21.

Fig. 23 is a cross-sectional view taken along line 2323 of Fig. 22.

Fig. 24 is a cross-sectional view taken along line 24-24 of ig. 22.

Fig. 25 is a broken view of a combination external spur and bevel earused in the centering device.

Fi 26 is a broken detailed View illustrating the mode of using thecentering device to position the rindin assemh ies of the presentinvention upon a crankshaft for a gri din eration.

Fi 27 is a br ken view illustrating a mode of checking the ia ter of hepin d ring inding.

Fi 28 is a side view of the illustration of Fi 27.

In the dr in numer l 10 desi n tes a portion of an engine cranksh ft.one rod pin of which is being ground bv use of a device m de inccordance with t e teachings of the present invention. The cr nkshaft 10is representative of the type commonlv used in loc motives. m rine andpower house work. and is shown wi h t main bearings or connecting rodand ston assemblies. En ines of this ty e are provided wi h inspecti nplates hi h mav be removed in order to ins ect r r m ve the crankshaft.It is to be understood at the beginning of this spe ification, h wever.that removal of the e tire rankshaft, as formerly required. is unnecessry with mv inventiou. In fact, a single scored or slightly out-of-roundpin may be ground in a few hours time where, according to the formerpractice, the shaft would be removed and requ re several days time of atwo-man crew for its repair.

In actual operation, as illustrated in Figs. 1 and 2, the device 18powered by means of a belt 11 and an electric motor 12. The motor may beanchored to the repair shop floor or may be placed upon a stand in closeproxunity to the engine and secured in proper alignment for the belt todrive the mechanism as will now be described.

In Fig. 4 of the drawing, it will be noted that the invention consistsof two assemblies designated generally by the numerals 13 and 14. Forconvenience of reference one assembly 13 will be referred to throughoutthe description as the grinding assembly and the other 14 will bereferred to as the gear train assembly. As seen in Fig. 4 these twoassemblies are made semi-circular and are finally bolted together bymeans of bolts 15. Dowels 16 and keys 17 further assist in securingalignment of the two assemblies into a true and perfect circle aroundthe pin 18 of the crankshaft 10.

The first problem presenting itself in the preparation of a machine ofthis type is that of securing concentric alignment between the grindingassembly and that of the pin to' be ground. As a simple solution to thisproblem I have provided a device constructed according to theillustrations of Figs. 21 through 25 of the accompanying drawings. Thisdevice consists of a ring 19 made of two semi-circular segments havingflanges 20 at their extremities so that the two halves may be boltedtogether in the manner shown. Bolts 21 and dowels 22 are placed throughthese flanges to secure the two halves together, and an aligning key 23is positioned in the abutting ends of each half.

One side face of the ring 19 is provided with a recess 24 of such depthand diameter as to slidably receive a ring gear 25. The ring gear 25 isalso made of two halves which are not tied together in any manner butare prevented from separating by being only slidably received in therecess 24 which is prepared for them. As shown in Fig. 25, the ring gear25 is provided with spur gear teeth 26 on its peripheral face while oneof its side faces is made into the form of a bevel gear 27. The ringgear 25 is held in its recess 24 by means of a cover plate 28 positionedover the recess and held by means of screws.

In Fig. 23, the cast ring 19 is shown as being provided with a raisedboss 29 through which 1 have positioned the shaft 30 of a small pinion31 enmeshed with the spur teeth of the ring gear 25. The outer end ofthe shaft is made square so that when a wrench is applied, the shaft maybe rotated and thus rotate the ring gear 25 by the pinion 31.

In Figs. 21 and 22, the ring 19 is also provided with radially extendingbosses 31'. These bosses are equally spaced circumferentially around thering 19 and provide a means of constructing an assembly as shown in Fig.24. Each boss 31' is slit transversely so that a small beveled pinion 32might be enmeshed with the beveled teeth of the ring gear 25. Eachpinion 32 is threaded internally to match the threads of a locating studdesignated by the numeral 33. The locating stud is positioned through ahole 34 drilled radially through the boss 31 so that the stud 33 may beadvanced toward or away from the center of the ring according to thedirection of rotation of its pinion 32. Since all of the pinions 32 aresimultaneously revolved by means of the ring gear 25, it is readily seenthat all of the studs 33 may be moved in or out simultaneously by meansof the shaft 30. In order to keep dirt and other foreign matter fromcollecting around the pinions 32, I have provided a sheet metal cover 35which covers the slot prepared for inserting the beveled pinion 32.

In the ring 19, I have provided a locating hole 36 with acorrespondingly positioned hole 37 in the ring gear 25 When removing thejoined assembly from around a crankshaft pin, it will be necessary toalign these two holes 36 and 37 so that the parting line of the splitgear 25 will coincide with the diametrical parting line of the ring 19.Thus the two complete halves may be readily disassembled by removing thelocking bolts 21. Around one peripheral side edge of the assembled ringis a turned surface 38 machined to a given dimension so that thegrinding assemblies can be properly located. To use the centeringmechanism as described above, the two halves of the ring 19 areassembled loosely over the rod pin 18 of the crankshaft 16 and thelocating studs brought to bear upon the pin by turning the shaft 30 inthe proper direction of rotation. In actual practice it has been foundthat the pins position the ring sufficiently at right angles to the axisof the shaft; but, if it is so desired, a dial indicator or othermeasuring instrument may be used to check for proper alignment. Asillustrated in Fig. 26, the ring 19 is positioned slightly away from themain flanges 39 of the crankshaft 1% with the machined surface 38thereof facing the flange.

It will be remembered that the main flanges of any crankshaft areconcentric with each other throughout the length of the shaft, so mycentering device may be used first upon one flange and then upon anotherin any given crankshaft.

Referring now to Figs. 3, 4 and 26, the following description willdisclose how I have provided two parallel side gears, bothconcentrically aligned with'the pin to be ground and which cooperatewith the gear train assembly 14 and the grinding assembly 13. In Fig. 3I have shown what I have termed an adapter, designated generally in thedrawing by the numeral 40. As in the case of all the other components,this adapter is also made into halves held together by bolts 41 andpositioning dowels 42. The complete adapter actually defines twoeccentric or overlapping circles, the upper and lower halves being heldrigidly together by means of the flanges 43 and 44 and by a web (notshown) placed at the point where the circles overlap. The inner ring 46is provided with a machined shoulder 47 of such diameter as to fitsnugly over the machined locating surface 38 provided on the ring 19.Thus, after positioning the centering device as formerly described, oneof the adapters 40 is located around the centering device and the twohalves thereof finally bolted together to form a perfect ring. The outerring of the adapter is provided with set screws 48 by means of which theadapter assembly is finally positioned on one of the flanges 39, asshown in Fig. 26. It will be remembered that the offset of the rod pin18 of the crankshaft 10 will vary with difference makes of engines andtherefore the adapters must be made accordingly. It will be rememberedalso that right and left hand adapters are necessary and each is mountedon opposing main flanges of the crankshaft by use of the centeringdevice as formerly described. Unless such a centering device is used,positive concentricity between the adapters is not possible, hence theother components will not operate properly. After each adapter has beenpositioned on the respective flanges 39, the centering device is removedaltogether from around the crank rod pin 18 so that the grindingassembly and the gear train assembly can be inserted. It will be notedfurther that the inner ring 46 on each adapter is provided with internalspur gear teeth 49.

Reference is now made to Figs. 6-11 for a description of the gear trainassembly 14. This assembly consists of a housing 50 made of cast metaland machined to a perfect half-circle as shown. Flanges 51 and 52 aremade to extend equidistantly from parallel side plates 53 and 54.Transverse flanges 55 and 56 are formed parallel to the diametral centerline of the housing to provide a means of connecting this assembly withthat of the grinding assembly 13 by means of bolts 57.

Between the two side plates 53 and 54 is a web 58 which serves not onlyas an anchoring wall for several of the gear shaft ends but which alsoforms one side wall for a pulley groove. The pulley 60, as seen in Fig.9, is made in two pieces and joined together to form a perfect circle.In the present instance I have provided tongues 61 on the ends of thelower half-section which,

are made to fit snugly into a corresponding groove provided on the upperhalf of the pulley. As illustrated in Figs. 10 and 11 the twohalf-sections of the pulley are finally secured together by placingscrews 62 through the side rims of the pulley and through the tongues61.

The peripheral face of the pulley is provided with a V notch 63corresponding in size and shape to a conventional V belt. The inner faceof the pulley is provided with a set of spur gear teeth 64 serving todrive the entire gear train which will be subsequently described.

When assembling the pulley 60, it is simply slipped into the preparedgroove 59 where it fits not too tightly so as to be permitted to revolveseparately and apart from the housing 50. To reduce the sliding frictionof this pulley, I have provided a construction as shown in Fig. 8.Spaced circumferentially around the housing 50 in several places I haveprovided rollers 65 rotatably journaled in the side wall 53 and the web58. These rollers are made in the shape of a spool with the wheels orflanges thereof straddling the internal gear portion 64 of the pulleyand riding against the side edges of the inner face. Thus the pulley mayroll freely upon these rollers when the same is revolved by means of thedriving belt 11 as shown in Fig. 1.

Fig. 6 will illustrate the manner of meshing the internal gear portionof the pulley 60 with the teeth of the first driving gear 66, and inFig. the transmission of power through the gear train follows in thisorder: from the first driving gear 66 through the pinion 67 to thedriven gear 68, through driving gear 69 to driven gear 70, from drivinggear 71 through the idler 72 to the driven gear 73. It will be notedthat the shaft of this driven gear 73 is bored to receive the shaft of afinal driving pinion 74. While the shaft of the final pinion 74 isslidably received in the bore provided in the shaft of the gear 73, itis keyed to the same so that it might rotate therewith. The purpose ofsuch construction is to allow the final pinion 74 to be moved into andout of engagement with the internal driving gear on its correspondingadapter, otherwise the housing could not be positioned between the twoadapters which have been previously mounted upon the main flanges 39 ofthe crankshaft 10. It will be further noted that I have provided amanually operable clutch 75 consisting simply of a yoke encircling aportion of the shaft of gear 74 with an opening 76 provided in thehousing 50 so the operators fingers may be inserted for operation of theclutch. While not shown in detail, each gear shaft and roller shaft isanchored in ball bearings so that the entire mechanism may be as freelyoperable as possible. The directions of rotation of the initial drivingpulley and the final output pinion have been made the same so that whenthe assembly is placed in the adapters, the pulley will be made torotate in the opposite direction. It is also highly important to notethat the speed ratio between the driving pulley and the final outputpinion 74 is extremely high, so that while the driving pulley 60 may berevolving at a relatively high rate of speed, the entire housing 50 ismade to revolve slowly in the opposite direction. By providing suchconstruction, perfect balance is maintained and the centrifugal forceimparted to the working components and the housing itself is kept to aminimum.

For a description of the grinding assembly 13 reference is now made toFigs. 12 through 20 of the accompanying drawing. In Fig. 12, theassembly housing 77 consists of a metal casting machined into thegeneral shape of that described for the gear train housing 59. The samepulley groove 59 is provided in the peripheral face of the housing 77 toreceive the pulley 60. Also not shown in these assembly views are therollers which are circumferentially spaced around the housing andconstructed in the manner illustrated in Fig. 8. The internal teeth 64of the pulley 60 are enmeshed with the first gear 78 of a gear trainarranged to rotate the grinding wheels which will be described later inthe specification. This gear 78, in turn, rotates a driving gear 79which, through an idler 80, rotates a pair of spaced gears 81 shown moreclearly in Fig. 13. In this figure the gear 81 is shown as provided witha pair of V grooves 32 spaced between the teeth. The gear is keyed toits shaft yet permitted to slide longitudinally along its shaft whilethe teeth of both gears 80 and 81 still remain in mesh. Since thehousing 77 is rotated in the opposite direction from that of the initialdriving pulley 60, as formerly described, it is readily apparent thatconsiderable speed is imparted to the final driving gear 82 whichimparts rotation to the grinding wheels by means of connecting belts 83.

The adjustable grinding wheel and support bracket consists of anarrangement of parts illustrated in Figs. 14, 15 and 16. Through aprepared boss 84 positioned on the housing 77 I have extended atight-fitting bushing 85 having an internal bore 86 adapted to receive aslid able standard 87 keyed to the bushing 85 by a key 88 to preventrotation. The standard 87 is also th eaded internally to receive athreaded adjusting stud 89. The stud 89 is provided with a flange 99arranged to receive the thrust in one direction while a suitable washer91 and lock nut 92 receive the thrust in the other direction. Theperipheral face of the washer is provided with machined indices 93 whichmay be brought into alignment with a positioning index (not shown) onthe upper face of the bushing 85. The upper end of the stud 89 is madehexagonal in the present instance so that by ap s ing a wrench to thesame, the stud may be turned in either direction of rotation to raise orlower the standard 37. The Washer 91 is rigidly afiixed to the stud forthe alignment of the indices to indicate given increments of raising orlowering.

At the lower end of the standard 87 I have provided a flange 94supporting a longitudinal feed slide bar 95 which is dovetailed on thetop side in the manner illustrated in Fig. 15. In the lower end of theinternally threaded standard 87 I have positioned a threaded stud 97with the lower portion thereof extended into slot 96 in the dovetail ofthe slide bar 95. The lower portion of this stud 97 is threadedtransversely to receive an adjusting screw 98, the head of which isrecessed into the side of the slide bar 95 and covered with a stop plate99. The screw 93 is actually a slotted hollow-head cap screw which maybe actuated by a wrench extended through an opening provided in thehousing 77. This construction permits the tightening or loosening of thedriving belts 83 which rotate the grinding wheels.

The base of the longitudinal slide bar 95 is also dovetailed into thewheel frame 100 to permit transverse movement of the whe ls across thepin journal as will be described later. The frame is provided with twospaced brackets 101 and 102 which support the grinding wheel shaft 103.As shown in Fig. 14, two grinding wheels 104 and are used, onepositioned on each end of the shaft 103. Between the spaced bosses 101and 102 I have provided a double pulley 106 which is keyed to the shaft103 and arranged to receive the belts 33. Thus the entire base 100 maybe moved transversely in the housing 77 by means of the dovetailed slidebar 95 as described, moving the rotating grinding wheels 104 and 105across the pin journal for grinding. Since the driving gear 81 of thegear train is free to slide along its shaft, the belts 83 will be heldin the proper driving alignment.

in order to keep the grinding wheels properly dressed, I have providedan arrangement illustrated in Fig. 12. Positioned through a boss 106provided on the housing 77, I have placed a shaft 107 having its upperend prepared to receive a wrench. The lower end of the shaft 107 isprovided with a bevel gear 108 having the teeth thereof entrained withthe teeth of another bevel gear 109. This latter gear 109 is fixed to atransversely positioned threaded shaft 110 which is threadedly extendedthrough the rear end of a diamond support bracket 111. To keep thesupport bracket 111 from revolving when the threaded shaft is rotated, lhave provided a guide rod 112 having its ends fixed in the side walls ofthe housing 77 and upon which the bracket may slide longitudinally. Theforward end of the support bracket is provided with a diamond pointedstud threaded through the bracket 111 with the end 113 carrying thedressing diamond protruding from the lower side of the bracket andpositioned just above the grinding wheels. Thus, the bracket may bemoved transversely across the housing and the threaded stud 110 byrotating the shaft 107. Since the diamond pointed stud 113 is threadedthrough the forward end of the support bracket 111, the diamond may bebrought lnto or out of engagement with the wheels for dressing. Theprocedure for rotating the wheels for dressing will be more clearlybrought out in the description of the gear train to follow.

As pointed out at the beginning of the specification, it is one of theobjects of the present invention to include mechanism for moving thegrinding wheels transversely across the rod pin they are intended togrind. As can be seen from the construction of the invention thus far,it is necessary that the mechanism for grinding be included in a spaceslightly narrower than the actual width of the pin journal, hence asingle grinding wheel having the fuil-face width of the journal couldnot be used. It is necessary, therefore, that either one or a pair ofwheels be used and that transverse movement be imparted to the wheels tocover the full-face width of the journal. In the present construction Ihave provided a pair of wheels, the overall width of which is muchnarrower than the face width of the journal; but, I have also providedmechanisms which permit the wheels to move across the journal forgrinding. In the present instance. one of the wheels will move to apoint adjacent one of the flanges 39 of the crankshaft 10, then thetravel will reverse and the entire assembly will be moved toward theother flange where the opposite wheel is permitted to grind the pin at apoint adjacent its corresponding flange. Thus the grinding by the twowheels actually overlaps near the center of the pin giving the effect ofhaving been ground by a single wheel of the full-pin width. Suchmechanism will be more clearly understood by reference to Figs. 17through 20 of the accompanying drawing.

In Fig. 18, I have provided a driving pinion 114 adapted for engagementwith the internal ring gear on one of the adapters formerly described.This pinion 114 is also provided with a manually operable clutch 115 sothat the gear may be moved into and out of engagement with the adaptergear, much in the same manner as the construction of the pinion 74described in the gear train assembly of Fig. 5. The shaft 116 of thispinion is fitted with a spline and slidably inserted into a boreprovided in a worm 117. This worm 117 is engaged by a worm gear 118, theshaft of which is extended and rotatably mounted in a prepared boss onthe housing 77. The length of the worm shaft is bored to slidablyreceive the shaft 119 of a bevel gear 122 as shown in Fig. 20. On theopposite end of shaft 119 I have placed a nut 121 keyed to the shaft butpermitted to move longitudinally thereon. On the inner face of the nut Ihave prepared serrations 121 matching serrations 120 formed on the endof the worm gear shaft 118. To prevent the nut 121 from slipping oif theend of the shaft 119 I have provided a retaining ring 118'.

Now it becomes apparent that as long as the nut 121 is engaged with theend of the worm shaft, that is, with the serrations of these twocomponents matched, power from the initial rotating gear 114 will betransmitted through the worm gear 118 to the nut 121, and finally to theshaft 119 which rotates the driving bevel gear 122. To disconnect thepower feed where the above movements may be made manually, it is onlynecessary to pull the nut outwardly and disengage the clutch facethereof from that of the end of the wormshaft. Since the nut 121 iskeyed to the shaft, the shaft may now be rotated by means of a wrenchapplied to the nut.

On the forward end of the shaft 119, in front of the worm gear 118 is abevel gear 122 simultaneously rotating two bevel gears 123 and 124.These gears are mounted so as to rotate freely upon a shaft 125 yet aresimultaneously rotated in opposite directions by means of the beveldriving gear 122. At the left hand end of the shaft 125 is a small spurgear 126 fixed to the shaft so as to rotate therewith. This spur gear126 is enmeshed with a similar spur gear 127 fixed to rotate withanother shaft 128. It will be noted that this last mentioned shaft 128is provided with a common screw thread, the purpose of which will besubsequently described. Engaged by the threads of the shaft 128 is adriving bar 129 the upper end of which is slidably mounted on astationary guide rod 130 and the lower end slidably mounted over anotherguide rod 131. Disposed centrally of the length of the shaft 125 is aclutch member 132 keyed to the shaft for rotation therewith butpermitted to slide longitudinally thereon. Both side faces of the clutchmember 132 are provided with serrations, matching serrations formed onthe face of each of the opposed beveled gears 123 and 124. It nowbecomes apparent that if the clutch 132 were moved to the left where itsserrations would mesh with those of the bevel gear 123, the shaft 125 isconnected to the threaded shaft 128 by the gears 126 and 127, thethreaded shaft 128 would be turned in a corresponding direction. Now ifthe clutch 132 were suddenly moved to become enmeshed with theserrations of the opposite gear 124, the shaft 125, and consequently theshaft 128. will be rotated in the opposite direction.

To accomplish such reverse movement, I have provided a yoke member 133placed in a prepared groove in the clutch member 132, the lower end ofwhich is rigidly mounted upon a guide rod 134, the ends of which arepermitted to s ide longitudinally in the side walls of the housing 77.Also arranged to be sl dably journaled in the side walls f the housingmember 77 is a forward rod 135. Rigidly affixed to the three rods 131,134 and 135 are two triangularly shaped brackets 136, one positionednear each of the ends of the aforementioned shafts. As seen in Fig. 19,between these brackets and the driving bar 129 I have placed compressionsprings 137 and 138. The forward rod 135 is shown in Fig. 17 as beingextended through a block 139 fastened to the inside of the housing bymeans of screws. The boss is drilled, as shown, to receive a small steelball 140 urged against the shaft 135 by means of a compression spring141 and an adjustable set screw 142. The forward shaft 135 is providedwith V notches 143 which are spaced apart for a distance equal to thedistance required to transfer the clutch 132 from engagement with one ofthe bevel gears to engagement with the other. In order to provide minuteadjustment for this distance I have provided set collars 144 and 145 onthe lower or forward rod 135.

From the above description the manner of reversing the traverse of thedriving bar 129 can be seen. When the bar 129 reaches one end of itstravel, as in Fig. 19, the lower end strikes the compression spring 137and begins to compress it. It will be remembered that when the clutch132 is engaged with one of the bevel gears 123 or 124, and the machineis in operation, it takes some little force to disengage the clutch andmove it into engagement with the other gear. Also, there is a pointbetween the two bevel gears 123 and 124 where the clutch would berunning idle if there were no outside force, such as a spring, to movethe clutch across this neutral position. The actual engagement of theclutch on one gear holds the clutch tightly until sufficient pressurecan be built up in the springs to finally disengage the clutch and moveit across this neutral position into engagement with the opposite gear.It will be noted further that on the upper ends of the connectingbrackets 136 I have provided contact arms 152 and 153 which receive thefinal thrust of the bar 129 at a point nearer the thrust point of theshaft 128, thus relieving the tendency of the bar to be cocked or tootherwise bind upon the threaded shaft 128. When the bar 129 finallyengages the contact arm 152, there is suflicient pressure built up inthe spring 137 to snap the clutch across the neutral position. The threeshafts 131, 134 and are all moved simultaneously since they are allconnected together by means of the brackets 136. The force on theforward shaft 135 causes the ball to be forced out of one notch andslipped into the other. Note that the action of the ball and spring tendto give the shaft a final, sudden push which assists in securelyengaging the teeth of the clutch against one of the bevel gears. Inother words, the ball and spring mechanism tends to hold all of theshafts together with the clutch in one position until sufficientpressure is built up in one of the springs 137 or 138, at which pointthe bar 129 has moved sufficiently across the shaft 123 to move theclutch across its neutral position. If such construction were notprovided, it is apparent that the clutch would simply be moved out ofengagement with one of the gears and simply rotate in a neutralposition.

Referring again to Fig. 14, it may be seen that the wheel frame here isprovided with a yoke 146 suitable for slidably receiving the front edgeof the driving bar 129 so that the driving bar, in its reciprocatorymovement may drive the grinding wheels backward and forward across thepin jounal.

In the present construction it is necessary that the driving bar bemoved to one side in order to reach the adjusting screw 98 describedelsewhere for applying tension to the grinding wheel driving pulleys 83.It now becomes apparent that the above described movement of the drivingbar can be accomplished in the same fashion by engaging the clutch ofthe manual control and applying a wrench to the prepared nut 121.

If desired, the construction according to that of Figs. 27 and 28 may beused which employs the use of a dial indicator with a gaging anvilcontacting the pin diameter. In these figures a gaging block 147 isplaced transversely across the diametral axis of the housing assembliesand a recess is bored into the outer face of the block at exactly 90degrees from this axis. The counterbore is then bored centrally toreceive the gaging stem 148 of a conventional dial indicator 149. Sincethe gaging stem is some four or five inches long in the presentinstance, I have prepared a guide tube 150 arranged to receive the stemto prevent any except longitudinal movement thereof. In this manner atrue and accurate reading of the gage may be obtained. The gage may beleft in the gage block 147 and held in position by means of set screws151; or, if desired, the entire indicator and stem may be inserted intothe block only periodically as a check. To use the instrument, it isnecessary to take an original reading before the grinding begins, anysubsequent readings being checked with the original to note the amountof material removed by grinding.

As a brief resume of a complete operation of the device, let it beassumed that the device is being used to grind a pin journal of a dieselengine. It will be remembered that it has been heretofore necessary toremove the entire crankshaft for this operation, a procedure which hasnot only been extremely expensive but tedious since all of theadjustments of the other portions of the crankshaft must be interferedwith.

With the present invention a single repairman can prepare the device foroperation in a few hours time. By removing the side plates from theengine, the crankshaft is exposed sufiiciently to remove the rod andpiston assembly. The oil, of course, is drained and the usualprecautions are taken for prohibiting the steel grindings from droppinginto the engine where they might prove dangerous. By using the centeringdevice, the two side adapters are quickly aligned over the side flangesof the crankshaft. The two gear train driving pinions 74 and 114 aremoved inwardly by their respective clutches to permit the two mainassemblies of the gear train assembly 13 and the grinding assembly to bepositioned in operative position on the adapters. The main drive pulley69, together with its driving belt 11, is then fitted over the twolocked assemblies. As before stated, any sort of prime mover may beemployed such as an electric motor as illustrated in the drawings. Byapplying a wrench to the shaft 89, the grinding wheels are lowered untilthey touch the face of the pin journal. After moving the driving pinions74 and 114 into engaged positions with their respective adapter gears,the machine is ready for operation. If the dial indicator mechanism isto be used to calculate the depth of grinding, an original reading isnoted with subsequent depths subtracted at each periodic checking. Anoriginal reading may also be taken on the calibrated washer 91 withsubsequent readings taken directly from the indices on the washer.

Since the depth of a single traverse of the grinding wheels isapproximately 4 or 5 thousandths of an inch, it is apparent that eventhe Worst scored pin or journal may be reground in a matter of minutes.

An unique feature of the present invention is that the grinding wheelsmay be power rotated while being dressed by the diamond dressing tool.To accomplish this, the driving pinion 74 (Fig. 5) is moved out ofengagement with the internal spur gear teeth of its respective adapterby use of the clutch 75. It will be remembered that this pinion is usedto rotate the entire machine in order to revolve the grinding wheelsaround the pin journal. By breaking this geared connection, the machineis made to remain stationary without affecting any of the otherassemblies since the gear train for rotating the grinding wheelsthemselves are operated by the revolving pulley 60.

Dis-assembly of the unit follows in the reverse order with the halves ofthe several assemblies being separated and removed from the shaft. Thusa pin is re-ground without removing the shaft from the engine andwithout dlilstirbing the bearing settings of the other portions of the sa t.

While the device contains precision made parts it is actually simple inits construction and so arranged that it may be operated by any noviceor apprentice. It is comparatively light in weight and since eachassembly is made in halves, it may be assembled and disassembled by asingle operator.

Other modifications or changes in the form of construction may also bemade without departing from the scope of my invention as defined in thefollowing claims.

I claim:

1. In a portable grinding machine, separable complementary housingsadapted to be removably connected together about a crankshaft pin, anadapter adapted to be connected to the flanges of a crankshaft pin forcentering said connected housings for rotation about said pin, meansconnected to one of said housings for rotating said connected housingsabout said pin, a grinding assembly in another of said housings, saidassembly comprising a grinding wheel adjustably arranged for grindingengagement with said crankshaft pin, and means for rotating saidgrinding wheel to grind the entire periphery of said crankshaft pin assaid connected housings are revolved about said pin.

2. In a portable grinding machine, complementary housings adapted to beconnected together about a crankshaft pin, an adapter adapted to beconnected to the flanges of a crankshaft pin for centering saidconnected housings for rotation about said pin, means connected to oneof said housings for rotating said connected housings about said pin, agrinding assembly in said housings, said assembly comprising a grindingwheel adjustably arranged for grinding engagement with said crankshaftpin, said grinding wheel being mounted for rotation about its axis andfor reciprocating movement longitudinally of the entire length of saidcrankshaft pin, and means for simultaneously rotating said grindingwheel and moving it longitudinally of said crankshaft pin to grind saidpin as said connected housings are revolved about said pin.

3. In a portable grinding machine, complementary housings adapted to beconnected together about a crankshaft pin, gearing in one of saidhousings for rotating said connected housings about said pin, a grindingassembly in another of said housings, said assembly comprising agrinding wheel shaft, a plurality of grinding wheels arranged on saidgrinding wheel shaft for grinding engagement with said crankshaft pin,said grinding wheels being mounted for rotation about their axes and forreciprocating movement longitudinally of said crankshaft pin, and meansfor simultaneously rotating said grinding wheels and moving themlongitudinally of the entire length of said crankshaft pin to grind saidpin as said connected housings are revolved about said pin.

4. In a portable grinding machine, complementary housings adapted to beconnected together about a crankshaft pin, gearing in one of saidhousings for rotating said connected housings about said pin, grindingassembly in said housings, said assembly comprising a plurality ofgrinding wheels adjustably arranged for grinding engagement with saidcrankshaft pin, said grinding wheels being mounted for rotation abouttheir axes and for overlapping reciprocating movement longitudinally theentire length of said crankshaft pin, and means for simultaneouslyrotating said grinding wheels and moving them longitudinally of saidcrankshaft pin to grind said pin as said connected housings are revolvedabout said pin.

5. In a portable grinding machine, complementary housings adapted to beconnected together about a crankshaft pin, an adapter for centering saidconnected hous ings for rotation about said pin, said housings beingprovided with a driving pulley formed of complementary segments andmounted for rotation on said housings, an internal gear on said drivingpulley, reduction gearing in one or' said housings selectivelyengageable with said internal gear for rotating said connected housings,a grinding assembly in the other of said housings, said assemblycomprising a grinding wheel ad ustaoly arranged for grindmg engagementWllil said crankshaft pin, said grinding wheel being mounted forrotation about its axis and for reciprocating movement longitudinally ofsaid crankshaft pin, and means selectively engageable with said internalgear for simultaneously rotating said grinding wheels and moving themlongitudinally of said crankshaft pin to grind said pm as said connectedhousings are revolved about said pin by rotation of said driving pulley.

6. In a portable grinding machine, complementary housings adapted to beconnected together about a crankshaft pm, an adapter for centering saidconnected housings for rotation about said pin, said housings beingprovided with a ring shaped driving pulley formed or complementarysegments and mounted for rotation on said connected housings, means forrotating said driving pulley, a driving gear on said driving pulley,reduction gearing in one of said housings selectively engageable withsaid driving gear for rotating said connected housings, a grindingassembly in said housings, said assembly comprising a grinding wheel adustably arranged for grinding engagement with said crankshaft pin, saidgrinding wheel being mounted for rotation about its axis and forreciprocating movement longitudinally of said crankshaft pin, and meansoperatively connected to said driving gear for simultaneously rotatingsaid grinding wheel and moving it longitudinally of said crankshaft pinto grind said pin as said connected housings are revolved about said pinby rotation of said driving pulley.

7. In a portable grinding machine, complementary housings adapted to beconnected together about a crankshaft pin, an adapter for centering saidconnected housings for rotation about said pin, said housings beingprovided with a circumferential groove, a ring shaped driving pulleyformed of complementary segments and mounted for rotation in saidgroove, means for rotating said driving pulley, an internal gear on saiddriving pulley, reduction gearing in one of said housings selectivelyengageable with said internal gear for rotating said connected housings,a grinding assembly in another of said housings, said assemblycomprising a plurality of grinding wheels adjustably arranged forgrinding engagement with said crankshaft pin, said grinding wheels beingmounted for rotation about their axes and for reciprocating movementlongitudinally of said crankshaft pin, and means operatively connectedto said internal gear for simultaneously rotating said grinding wheelsand moving them longitudinally of said crankshaft pin to grind said pinas said connected housings are revolved about said pin by rotation ofsaid driving pulley.

8. In a portable grinding machine, two complementary semi-circularhousings adapted to be aligned and connected together in a circle abouta'crankshaft pin, a plurality of adapters for centering said connectedhousings for rotation about said pin, said housings being provided witha circumferential groove, a ring shaped driving pulley formed ofcomplementary semi-circular segments and mounted for rotation in saidgroove, means for rotating said driving pulley, anfinternal gear on saiddriving pulley, reduction gearing in one of said housings selectivelyengageable with said internal gear for rotating said connected housings,a grinding assembly in the other of said housings, saidasse'mblycomprising a plurality of grinding wheels adjustably arranged forgrinding engagement with said-crankshaft pin; said grinding wheels beingmounted for'rotationabout their axes and for reciprocating movementlongitudinally of said crankshaft pin, and means operatively connectedto said internal gear for simultaneously rotating said grinding wheelsand moving them longitudinally of said crankshaft pin to grind said pinas said connected housings are revolved about said pin by rotation ofsaid driving pulley.

References Cited the file of this patent UNITED STATES PATENTS 132,109Shrewsbury Oct. 8, 1872 730,123 Hudson June 2, 1903 961,969 KlingloffJune 21, 1910 1,026,022 Cremean May 14, 1912 1,326,091 Porter Dec. 23,1919 1,464,728 Ross Aug. 14, 1923 1,748,343 Gustafsson Feb. 25, 19301,919,790 Kottman July 25, 1933 1,956,068 Herzog Apr. 24, 1934 1,998,755Giflin Apr. 23, 1935 2,138,258 Sievers Nov. 29, 1938 2,171,417 McGovernet a1 Aug. 29, 1939 2,282,918 Zawistowski May 12, 1942 2,455,742 DorianDec. 7, 1948 2,566,660 Georgian Sept. 4, 1951 FOREIGN PATENTS 223,433Germany June 21, 1910 255,664 Italy Oct. 31, 1927 323,437 Great BritainJan. 2, 1930 329,992 Germany Dec. 2, 1920 403,300 Germany Sept. 26, 1924

